Yeast is a living entity that comes to life with the addition of sugar and proofing. Yet, yeast that has been stored too long loses its freshness and eventually, the yeast dies and cannot be revived. If you're not sure how long that yeast has been in the pantry for, test its viability.

Steps

1

Remove one sachet of the yeast from the packet, or a teaspoon of loose yeast from a container.

Check once the 15 minutes has passed. Live yeast will cause the surface to bubble and this means the yeast is good and will work in your baking. On the other hand, if there is no sign of activity after 15 minutes have passed, the yeast is no good and should be discarded.